Ball-bearing jack.



No. 804,662. PATENTED NOV. 14., 1905. H. G. JOHNSTON.

BALL BEARING JACK.

APILICATION FILED MAY 11. 1905.

UN ITED STATES PATENT OFFICE.

BALL-BEARING JACK.

Specification of Letters Patent.

Patented Nov. 14, 1905.

Application filed May 11, 1905. Serial No. 260,048.

To a. whom it play concern:

Be it known that 1, Homer. G. J OHNSTON, a citizen of the United States,residing at (Jorsicana, in the county of Navarro and State of Texas,have invented certain new and useful Improvements in Ball-Bearing Jacks;and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to improvements in jacks; and the object in viewis the provision of a structure susceptible of elevating heavy weightswith a minimum amount of wear.

\Vith this and other objects in view the invention comprises certainnovel constructions, combinations, and arrangements of parts, as will behereinafter fully described and fully explained in the accompanyingdrawings.

Figure 1 represents a longitudinal vertical central section takenthrough the jack em bodying the features of the present invention, partsbeing in elevation. Fig. 2 represents a detail view of thebearing-retainer.

Referring to the drawings by numerals, 1 indicates a hollow base orstand, the lower end of the stand being closed and an opening beingformed in the closure of such end and filled normally by a preferablythreaded stopper 2. The interior of the stand 1 is divided by aninwardly-projecting annular flange 3 into a lower chamber- 1 and anupper chamber 5. An internally-threaded bushing 6 is arranged within thechamber 5 and rests upon the flange 3, said bushing being fixed in saidchamber against rotation, and a threaded shaft or jack-screw is threadedthrough the bushing 6. WVhen said screw is at the lower extreme of itsmovement, its lower end is spaced, preferably, only a short distanceabove the stopper 2. Of course the screw may be of any desired length.The upper end of the screw 7 is formed integrally with or suitablysecured to a preferably annular head 8 with the aperture or apertures 9adapted to receive a rotating tool. Projecting upwardly from the head 8in axial alinement with the screw 7 is a shaft 10, formed at its upperend with an annular groove 11. An annulus or ring 12, preferably oftool-steel, surrounds the shaft 10 and is supported on the head 8. A

bearing-retainer 13 surrounds the shaft 10 above the ring 12, saidretainer consisting of a ring formed with a series of apertures, eachdesigned to retain a ball or other suitable antifriction-bearing 14: 14,said ring being formed with a depending flange 15, extending downwardlyinto contact with the upper surface of the ring 12 and positioned forsupporting the main portion of the bearing-retainer out of contact withthe ring 12. Inclosing the upper end of the shaft 10 is a cap 16,carrying a pin 1'7, preferably threaded through the side wall of the capand extending into the groove 11 in position for preventing verticaldisplacement of the cap while permitting rotation thereof. The loweredge of the depending walls of the cap 6 rests upon the bearings 14,said bearings 11 in turn resting upon the ring 12.

In operation the chamber I is filled with oil or other suitablelubricant, and the jack may be placed beneath the object to be elevatedand an operating-tool introduced into the aperture 9. The movement ofsaid tool about the jack will of course cause the head 8 to be elevatedunder the action of the screw 7 until the cap 6 engages the article tobe supported and elevates the same to the distance required. Of courseit is wholly immaterial whether the jack is placed beneath the object tobe elevated or the converse operation occurs, the use of jacks beingnumerous and varied and well understood in the art. As the head 8rotates the balls take up friction between the disk 12 and the cap 16.Continued operation of the jack will eventually wear away the uppersurface of the ring 12, and as soon as such wearing comes to the extentof lessening the utility of the jack it is only necessary to withdrawthe pin 17, remove the cap 16 and the retainer 13, and lifting off thering 12 invert the same and present the unworn under surface thereof asthe upper or new wearing surface. The parts being in place, the partswill be in substantially as good a condition as if a new ring had beeninserted.

What I claim is- 1. A jack comprising a stand, a screw engaging thesame, a head on said screw, a reversible ring carried by said head, anda cap supported above said ring.

2. A jack comprising a casing, a screw engaging the same, a head forsaid screw, a reversible ring supported above said head, a cap spacedabove said ring, and an antifrictionbearing disposed above said ring.

3. A jack comprising a stand, a screw engaging the same, a head for saidscrew, a cap spaced above said head, an apertured ring interposedbetween said head and cap, a supporting-flange depending from said ring,and

antifriction-bearing's carried in the apertures of said ring in positionfor supporting said cap.

4. A jack comprising a stand,'a screw threaded into the same, a head forsaid screw, a shaft projecting from said head, a cap surrounding saidshaft, an apertured ring surrounding said shaft and interposed betweensaid cap and head, a flange extending from the inner edge of said ringand supporting the same out of contact with the head, andantifriction-bearings arranged in the apertures of said ring.

5. A jack comprising a stand, a screw engaging the same, a head for saidscrew, a cap spaced from said head, an apertured body interposed betweensaid head and cap, and arranged out of contact with either, andantifriction-bearings arranged in the apertures in said body in positionfor supporting said cap.

6. A jack comprising a stand, a screw engaging the same, a head for saidscrew, a shaft projecting from said head, a removable ring surroundingsaid shaft and supported by said head, a second ring also surroundingsaid shaft and provided with a depending flange engaging thefirst-mentioned ring, said second ring being formed with apertures,antifrictionbearings arranged in said apertures in position for restingupon said first-mentioned ring, and a cap resting upon said bearings.

7 A jack, comprising a stand, a screw engaging the same, a head for saidscrew, a shaft extending vertically from said head, acap provided withan annular, depending portion positioned upon the upper end of saidshaft, an apertured body interposed between said head and the annular,depending portion of said cap and arranged out of contact with either,and antifriction-bearings arranged in the apertures of said body andpositioned for supporting said cap.

8. A jack, comprising a stand, a screw engaging the same, a head forsaid screw, a shaft extending from said head, a cap positioned upon saidshaft, adepending extension formed upon said cap and surrounding saidshaft, and an antifriction-bearing arranged between the lower edge ofsaid depending extension of the cap and head.

In testimony whereof I affix my signature in presence of two Witnesses.

HORACE G. JOHNSTON.

Witnesses:

W. J. CHENEY, R. N. ELLIOTT.

